基于虚拟同步发电机的微电网电能质量控制

Power Quality Control of Microgrid Based on Virtual Synchronous Generator

交直流混合微电网(HMG)因兼顾了交流微电网和直流微电网的优点,得到越来越广泛的研究和应用,其中连接2个子网间的互联变流器(ILC)是维持交直流HMG稳定运行的关键。针对现有交直流HMG电能质量的研究,其交流子网频率和直流子网母线电压通常偏离额定值,属于有差调节。基于此,提出了一种基于虚拟同步发电机(VSG)的ILC控制策略,该策略不仅能使交直流HMG在并网运行和离网运行两种模式下的交流频率和直流母线电压始终维持在额定值,同时还能平滑交直流HMG中各单元的输出。最后搭建实验样机验证了所提策略的有效性。

AC/DC hybrid microgrids(HMG) are being studied and applied more and more widely because they take into account the advantages of both AC microgrids and DC microgrids.The interlinking converters(ILC) connecting the two sub-grids are the key to maintain the stability of AC/DC HMG.Aiming at the research on the power quality of the existing AC/DC HMG,the frequency of the AC sub-network and the bus voltage of the DC sub-network usually deviate from the rated value,which belongs to the differential regulation.Based on this,an ILC control strategy based on virtual synchronous generator(VSG) is proposed,which can not only make the AC frequency and DC bus voltage of the AC/DC HMG in grid-connected operation mode and off-grid operation mode maintain rated value all the time while smoothing the output of each unit in an AC/DC HMG.Finally,an experimental prototype is built to verify the effectiveness of the proposed strategy.